The government will come up with a drastic plan by April to deal with a major electricity shortage expected this summer from the loss of two nuclear power plants damaged by the quake and tsunami in Fukushima Prefecture.

Options being considered include the introduction of daylight-saving time, known locally as “summer time,” and a hike in electricity charges, although nothing has been decided yet.

When electricity use peaks to escape the heat and humidity this summer, it is expected to create a shortage of around 10 million kw — or nearly 20 percent of total available power — Chief Cabinet Secretary Yukio Edano said upon emerging from an emergency meeting on the problem earlier in the day.

“There needs to be a drastic and immediate measure that may affect industrial business activities and people’s lifestyles to fill in the gap” between supply and demand, Edano said.

The power shortage has affected the entire Kanto plain. As an emergency measure, Tokyo Electric Power Co., which manages the nuke plants, was forced to initiate rolling blackouts for the first time to prevent a wider, regionwide blackout.

Edano stressed, however, that other measures will need to be taken.

“We will put our heads together to find a way that will not affect the people’s lives or Japan’s business and economy, and one that will not rely on rolling blackouts,” Edano said.

“But I cannot predict the outcome.”

Among the medium-term steps explored at the emergency meeting was the idea of building new thermal power plants, which would help allay growing public concern about nuclear power as the plants in Fukushima continue to spew radiation, industry minister Banri Kaieda said.

“If we see a heat wave like last summer’s, the gap could reach a maximum of 15 million kw . . . so we have decided to work out a policy package ahead of the summer peak,” he said.

That number represents about a fourth of Tepco’soriginal power generating capacity.